Wire-feeding mechanism for nail-making machine



June 18, 1957 F. A. CLARY, JR.,' ETAL 2,796,168

WIRE-FEEDING MECHANISM FOR NAIL-MAKING MACHINE Original Filed on. a, 1951 2 Sheets-Sheet 1' 29 5 n4 In I 3 w -12? '1.% :4 "I- In. I 23 I A F1 4 I5 I rs;

IN V EN TOR/S FRANK A-CLARY, JR.

GRANT N. WILLIS 'maa ATTORNEYS June 18, 1957 F. A. CLARY, JR; ETAL 2,795,168

WIRE-FEEDING MECHANISM FOR NAIL-MAKING MACHINE 2 Sheets-Sheet 2 Original Filed Oct. 3. 1951 INVENTORS FRANK A. CLARY, J R.

GRANT N WILLIS BY flak", Girdle; V7

THER ATTORNEYS United States Patent ce WIRE-FEEDING MECHANISM FOR NAIL-MAKING MACHINE Frank A. Clary, Jr., and Grant N. Willis, Bristol, Conn., assignors to Pittsburgh Steel Company, Pittsburgh, Pa., a corporation of Pennsylvania Original application October 3, 1951, Serial No. 249,436, now Patent No. 2,767,411, dated October 23, 1956. Divided and this application May 12, 1954, Serial No. 429,212

1 Claim. (Cl. 203-150) The present invention relates to machines for making wire nails and has for its principal object the provision of a machine capable of operating safely at a higher speed of production than has heretofore been possible with machines of the same general type.

The feature of novelty of the present invention resides in the feeding mechanism, which provides for rapid and positive gripping and release of the wire, and for positive feeding of the wire to the heading mechanism.

The above and other advantageous features of the in- 'VCDllOIl will hereinafter more fully appear from the following description, considered in connectionwith the accompanying drawings, in which:

Fig. 1 is a plan view of a nail-making machine embodying the present invention.

Fig. 2 is a side elevation of the machine shown in Fig. 1.

Fig. 3 is a longitudinal sectional view on line 3-3 of Fig. 1. a I

Fig. 4 is a sectional detail showing the wire-feeding mechanism on an enlarged scale.

'Fig. 5 is a fragmentary sectional view on line 5-5 of Fig. 4.

Figs. 6 and 7 are diagrams illustrating the operation of the wire-feeding mechanism shown in Fig. 4.

The present application is a division of our application Serial No. 249,436 filed October 3, 195 1, and now Patent 2,767,411.

Referring first to Figs. 1 and 2, the working parts of the machine are mounted on a frame 1 of heavy construction, which frame is supported on a base 2, so that the wire W can enter the machine at a convenient height above the floor. The wire W is shown as entering the machine from the right, as viewed in Fig. 1, after passing through a number of straightening rolls 3 mounted on a bracket 4 extending from the frame 1.

The wire W is adapted to be intermittently fed into the machine by means of a reciprocating feeding device 5, which when moved to the left projects the wire W through a heavy anvil block 6 between a pair of grippers 7 movable at right angles to the travel of the wire. A pair of knives 8 are also movable at right angles to the line of wire feed and when closed, serve to cut off a completed nail which is then struck by an ejector 9 rotating in a space between the knives 8 and a heading ram 10, then in a retracted position.

After a completed nail has been cut from the wire W by the knives 8, the protruding end of the wire is held between the grippers 7 and this protruding portion is swaged to form a nail head by the impact of the ram 10 which is backed up by the block 6 behind the grippers 7. The above described general operating cycle is then repeated upon opening of the grippers 7 to permit the feeding device 5 to again move the wire W an amount which determines the length of the completed nail that is cut by the next closing of the knives 8.

The above described elements of the machine are driven from a main shaft 11 supported in bearings 12 mounted in the frame 1, with one end of the shaft Patented June 18, 1957 11 being provided with a pulley 13 connected by a belt 14 to a suitable source of power such as an electric motor 15.

As previously pointed out, the wire W is adapted to be intermittently fed into the machine by means of a reciprocating feeding device 5. The feeding device 5 consists of a carriage 111 that is supported for horizontal movement on a guide 112 extending between lugs 113 provided by the frame 1. The carriage 111 is adapted to be moved back and forth by means of a connecting rod 114, the ends of which are mounted on pins 115 and 116 provided by a crank disc 117 and the carriage 111, respectively. The crank disc 117 is mounted on the end of a shaft which is connected by gearing to a countershaft 27.

Therefore, rotation of the shaft will impart reciprocating movement to the carriage 111, and this movement is utilized to operate a wire feeding device, the details of which are shown on an enlarged scale in Fig. 4. The upper end of the carriage 111 serves to support a feeding head 120 which extends upwardly through a slot 121 provided in the top of the frame 1, and extending parallel to the upper guide 112a on which the carriage moves. The head 120 has a bore 122 through which extends a stud 123, the stud being formed with a slot 124 through which the wire W passes freely. The stud 123 extends above the head 120 and serves to receive a pair of shoes 125 that are in the form. of flat washers composed of Wear resistant material, between which the wire passes.

The shoes 125 are formed with grooves 126 f0r receiving the wire W, see Fig. 5, and the shoes are yieldingly held in engagement with opposite sides of the wire by means of a spring 127 surrounding the stud 123. The upper end of the spring 127 is seated in a recess 128 provided in the head 120, while the lower end of the spring bears on the top of a flange 129 secured to the lower end of the stud 123. Therefore, the spring 127 normally exerts a downward pull on the stud 123, which pull is transmitted to the shoes 125 through a nut 130 on the stud to cause the wire W to be closely gripped by the shoes 125.

The pressure exerted on the wire by the shoes 125 can be adjusted by means of the nut 130, which is threaded on the upper end of the stud 123. The location of the nut 130 determines the position occupied by the lower end of the stud 123, and with the stud free of any force opposing the downward pressure exerted by the spring, the spring loading is such as to cause the shoes 125 to exert a pressure of 300 pounds on the wire W while the carriage 111 is traveling through its feeding stroke, which is to the left, as viewed in Fig. 3.

Fig. 3 shows the position occupied by the carriage 111 at the end of the wire-feeding stroke, in which the head 120 is near the left-hand end of the slot 121. At this moment, a nail N with a head formed thereon has been fed beyond the grippers 7 in readiness to be severed from the wire by closure of the knives 8. It is to be noted that in this position, the crank pin 115 is substantially on left dead center, and that the lower end of the stud 123 is just being engaged by a cam projection 131 formed on the surface of a sleeve 132 which forms part of the outer end of the connecting rod 114. Therefore, when the carriage 111 starts its return movement to the right by turning of the crank 117 in a clockwise direction, turning of the sleeve 132 about the pin 116 in a counterclockwise direction will cause the cam projection 131 to force the stud 123 upwardly, as indicated by the arrow in Fig. 6, and thereby compress the spring 127 sufiiciently to release the pressure of the shoes 125 on the wire.

The cam projection 131 will continue to engage the stud 123, as the crank disc 137 completes one half of a revolution, so that movement of the feeding head 120 be moved in opposite directions.

in the slot 121, in preparation for another feed of the wire, will take place without any appreciable drag by the shoes 125 on the wire, which at that time is firmly held between the grippers 7. However, as soon as the crank p in' 115 passes beyond right dead center and "starts movement of the carriage 111 to. the ten, clockwise turning of the sleeve 132, as shown in Fig. 7, will disengage the cam projection 131 from the stud 123, so

that the spring 127 will again exert a downward pull on the stud 123 to cause the wire W to be engaged by the shoes 125 with a force 'sufiicient to feed the wire between the grippers 7.

As a result of the functioning of the above described feeding mechanism, each complete revolution of the shaft will cause a predetermined length of wire to be fed, after which the carriage 111 will 'beretracted to position the head 1 20 for the next feed. The length of wire that is fed by each movement of the carriage 111 is determined by the displacement of the crank pin 115 on the disc 117 with respect to the axis of the shaft, and

moved between the ways 134 in either direction'so as to vary the distance between the pin 1'15 and the axis of the shaft 118.

In order to balance the shaft 118, the crank disc 117 provides-a counterweight 137 on the opposite side 1o'f;the shaft axis from the pin 115. This counterweight 137 is also adjustable on the ways 134 by means of -the screw 135 which is threaded into the counterweight. The threads on the screw 135 are such that turning thereof will cause the block 133 and the counterweight 137 to In this way, movement of the pin 1'15 toward or away from the shaft 118 will result in movingth'e counterweight 137 a corresponding distance, thereby keeping the shaft in balance for any given setting of the crank pin 115.

By reason of the above described cooperation between the end of the stud 123 and the cam projection 131, it

is obvious that the shoes 125 will either engage'or'release the wire in accordance with the direction of movement of the carriage 111 by the connecting rod 114. In other words, the duration of the engagement of the cam projection 131 with the stud 123 is determined entirely by the degree of turning movement of the connecting rod 114 on its pin 116.

Furthermore, any variations in the diameter of "the wire being handled, within customary tolerances, does not appreciably affect operation of the feeding device, because the shoes 125 either engage the wire with the full loading of the spring 127, or release the wire when the stud 123 is positively relieved from the pressure of the spring 127 by engagement with the cam projection 131.

According to the provisions of the patent statutes, we have explained the'prin'ciple of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within-the'scope of the appended claim, the invention maybe practiced otherwise than as specifically illustrated and described.

We claim:

In a nail-making machine a wire feeding mechanism comprising in combination a rotatable shaft, a slide movable back and forth by a connecting rod extending between said slide and a crank on said shaft, a stud movable with said slide, a pair of shoes mounted on said stud for receiving wire therebetween, and a spring surrounding the stud for causing said shoes to closely engage the wire, with one end of said stud bearing on a cam provided on one endof said connecting rod, so that turning of said cam in one direction willmove said stud against the pressure of said spring'to release the shoes from the wire, while turning of said cam in the opposite direction will permit the spring to hold said shoe in close engagement with thewire.

References Cited in the file of this patent UNITED STATES PATENTS 293,538 Sunderland Feb. 12, 1884 297,472 Terrell Apr. 22, 1884 671,412 Chambers Apr. 2, 1901 2,696,380 Adams Dec. 7, 1954 

